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1.
Eur J Neurosci ; 59(7): 1500-1518, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38185906

ABSTRACT

Discrete alcohol cues and contexts are relapse triggers for people with alcohol use disorder exerting particularly powerful control over behaviour when they co-occur. Here, we investigated the neural substrates subserving the capacity for alcohol-associated contexts to elevate responding to an alcohol-predictive conditioned stimulus (CS). Specifically, rats were trained in a distinct 'alcohol context' to respond by entering a fluid port during a discrete auditory CS that predicted the delivery of alcohol and were familiarized with a 'neutral context' wherein alcohol was never available. When conditioned CS responding was tested by presenting the CS without alcohol, we found that augmenting glutamatergic activity in the nucleus accumbens (NAc) shell by microinfusing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) reduced responding to an alcohol CS in an alcohol, but not neutral, context. Further, AMPA microinfusion robustly affected behaviour, attenuating the number, duration and latency of CS responses selectively in the alcohol context. Although dopaminergic inputs to the NAc shell were previously shown to be necessary for CS responding in an alcohol context, here, chemogenetic excitation of ventral tegmental area (VTA) dopamine neurons and their inputs to the NAc shell did not affect CS responding. Critically, chemogenetic excitation of VTA dopamine neurons affected feeding behaviour and elevated c-fos immunoreactivity in the VTA and NAc shell, validating the chemogenetic approach. These findings enrich our understanding of the substrates underlying Pavlovian responding for alcohol and reveal that the capacity for contexts to modulate responding to discrete alcohol cues is delicately underpinned by the NAc shell.


Subject(s)
Cues , Nucleus Accumbens , Humans , Rats , Animals , Nucleus Accumbens/physiology , Rats, Long-Evans , alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid , Ethanol/pharmacology , Conditioning, Operant/physiology
2.
Chemistry ; 30(27): e202400132, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38441728

ABSTRACT

We report a series of Pd(II)nL2n coordination rings for which nuclearity is controlled by the binding angle of the corresponding bis-monodentate bridging ligands. Judicious choice of the angle within a family of rather rigid ligands allowed for the first-time to synthesize a homoleptic five-membered Pd5L10 ring that does not require any template to form. We demonstrate that control over the ring size is maintained both in the solid-, solution-, and gas-phase. Two X-ray structures of five-membered rings from ligands with ideal angles (yielding a perfect pentagonal ring) vs. suboptimal angles (resulting in a highly distorted structure) illustrate the importance of the correct ligand geometry. A mathematical model for estimating the expected ring size based on the ligand angle was derived and DFT computations show that ring-strain is the major factor determining the assembly outcome.

3.
Bioorg Chem ; 147: 107359, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38613925

ABSTRACT

Twenty N-substituted pyrrolo[3,4-c]quinoline-1,3-diones 3a-t were synthesized by a cyclization reaction of Pfitzinger's quinoline ester precursor with the selected aromatic, heteroaromatic and aliphatic amines. The structures of all derivatives were confirmed by IR, 1H NMR, 13C NMR and HRMS spectra, while their purity was determined using HPLC techniques. Almost all compounds were identified as a new class ofpotent inhibitors against hDHODH among which 3a and 3t were the most active ones with the same IC50 values of 0.11 µM, about seven times better than reference drug leflunomide. These two derivatives also exhibited very low cytotoxic effects toward healthy HaCaT cells and the optimal lipophilic properties with logP value of 1.12 and 2.07 respectively, obtained experimentally at physiological pH. We further evaluated the comparative differences in toxicological impact of the three most active compounds 3a, 3n and 3t and reference drug leflunomide. The rats were divided into five groups and were treated intraperitoneally, control group (group I) with a single dose of leflunomide (20 mg/kg) group II and the other three groups, III, IV and V were treated with 3a, 3n and 3t (20 mg/kg bw) separately. The investigation was performed in liver, kidney and blood by examining serum biochemical parameters and parameters of oxidative stress.


Subject(s)
Dihydroorotate Dehydrogenase , Enzyme Inhibitors , Oxidoreductases Acting on CH-CH Group Donors , Animals , Humans , Male , Rats , Cell Line , Dose-Response Relationship, Drug , Drug Discovery , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Molecular Structure , Oxidoreductases Acting on CH-CH Group Donors/antagonists & inhibitors , Oxidoreductases Acting on CH-CH Group Donors/metabolism , Pyrroles/chemistry , Pyrroles/pharmacology , Pyrroles/chemical synthesis , Quinolines/chemistry , Quinolines/pharmacology , Quinolines/chemical synthesis , Rats, Wistar , Structure-Activity Relationship , Quinolones/chemical synthesis , Quinolones/chemistry , Quinolones/pharmacology
4.
Phys Chem Chem Phys ; 25(10): 7176-7183, 2023 Mar 08.
Article in English | MEDLINE | ID: mdl-36810584

ABSTRACT

The electrical properties of large area molecular devices consisting of gold nanoparticles (GNPs) sandwiched between a double layer of alkanedithiol linkers have been examined. These devices have been fabricated by a facile bottom-up assembly in which an alkanedithiol monolayer is first self-assembled on an underlying gold substrate followed by nanoparticle adsorption and then finally assembly of the top alkanedithiol layer. These devices are then sandwiched between the bottom gold substrates and a top eGaIn probe contact and current-voltage (I-V) curves recorded. Devices have been fabricated with 1,5-pentanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol and 1,10-decanedithiol linkers. In all cases the electrical conductance of the double SAM junctions with GNPs is higher than the corresponding and much thinner single alkanedithiol SAM. Competing models for this enhanced conductance are discussed and it is suggested to have a topological origin arising from how the devices assemble or structure during the fabrication, which gives more efficient cross device electron transport pathways without the GNPs producing short circuits.

5.
Arch Pharm (Weinheim) ; 356(2): e2200374, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36372522

ABSTRACT

Fourteen novel quinoline-4-carboxylic acid-chalcone hybrids were obtained via Claisen-Schmidt condensation and evaluated as potential human dihydroorotate dehydrogenase (hDHODH) inhibitors. The ketone precursor 2 was synthesized by the Pfitzinger reaction and used for further derivatization at position 3 of the quinoline ring for the first time. Six compounds showed better hDHODH inhibitory activity than the reference drug leflunomide, with IC50 values ranging from 0.12 to 0.58 µM. The bioactive conformations of the compounds within hDHODH were resolved by means of molecular docking, revealing their tendency to occupy the narrow tunnel of hDHODH within the N-terminus and to prevent ubiquinone as the second cofactor from easily approaching the flavin mononucleotide as a cofactor for the redox reaction within the redox site. The results of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that 4d and 4h demonstrated the highest cytotoxic activity against the A375 cell line, with IC50 values of 5.0 and 6.8 µM, respectively. The lipophilicity of the synthesized hybrids was obtained experimentally and expressed as logD7.4 values at physiologicalpH while the solubility assay was conducted to define physicochemical characteristics influencing the ADMET properties.


Subject(s)
Chalcones , Dihydroorotate Dehydrogenase , Quinolines , Humans , Chalcones/pharmacology , Dihydroorotate Dehydrogenase/antagonists & inhibitors , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Molecular Docking Simulation , Quinolines/pharmacology , Quinolines/chemistry , Structure-Activity Relationship
6.
Breast Cancer Res Treat ; 191(3): 665-675, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34988767

ABSTRACT

PURPOSES: To delineate operational changes in Kaiser Permanente Northern California breast care and evaluate the impact of these changes during the initial COVID-19 Shelter-in-Place period (SiP, 3/17/20-5/17/20). METHODS: By extracting data from institutional databases and reviewing electronic medical charts, we compared clinical and treatment characteristics of breast cancer patients diagnosed 3/17/20-5/17/20 to those diagnosed 3/17/19-5/17/2019. Outcomes included time from biopsy to consultation and treatment. Comparisons were made using Chi-square or Wilcoxon rank-sum tests. RESULTS: Fewer new breast cancers were diagnosed in 2020 during the SiP period than during a similar period in 2019 (n = 247 vs n = 703). A higher percentage presented with symptomatic disease in 2020 than 2019 (78% vs 37%, p < 0.001). Higher percentages of 2020 patients presented with grade 3 (37% vs 25%, p = 0.004) and triple-negative tumors (16% vs 10%, p = 0.04). A smaller percentage underwent surgery first in 2020 (71% vs 83%, p < 0.001) and a larger percentage had neoadjuvant chemotherapy (16% vs 11%, p < 0.001). Telehealth utilization increased from 0.8% in 2019 to 70.0% in 2020. Times to surgery and neoadjuvant chemotherapy were shorter in 2020 than 2019 (19 vs 26 days, p < 0.001, and 23 vs 28 days, p = 0.03, respectively). CONCLUSIONS: During SiP, fewer breast cancers were diagnosed than during a similar period in 2019, and a higher proportion presented with symptomatic disease. Early-stage breast cancer diagnoses decreased, while metastatic cancer diagnoses remained similar. Telehealth increased significantly, and times to treatment were shorter in 2020 than 2019. Our system continued to provide timely breast cancer treatment despite significant pandemic-driven disruption.


Subject(s)
Breast Neoplasms , COVID-19 , Delivery of Health Care, Integrated , Breast Neoplasms/diagnosis , Breast Neoplasms/epidemiology , Breast Neoplasms/therapy , Female , Humans , Pandemics , SARS-CoV-2
7.
Molecules ; 27(13)2022 Jun 23.
Article in English | MEDLINE | ID: mdl-35807288

ABSTRACT

Polyphenolic compounds are used for treating various diseases due to their antioxidant and anticancer properties. However, utilization of hydrophobic compounds is limited due to their low bioavailability. In order to achieve a greater application of hydrophobic bioactive compounds, hydrogel beads based on biopolymers can be used as carriers for their enhanced incorporation and controlled delivery. In this study, beads based on the biopolymers-κ-carrageenan, sodium alginate and poloxamer 407 were prepared for encapsulation of curcumin. The prepared beads were characterized using IR, SEM, TGA and DSC. The curcumin encapsulation efficiency in the developed beads was 95.74 ± 2.24%. The release kinetics of the curcumin was monitored in systems that simulate the oral delivery (pH 1.2 and 7.4) of curcumin. The drug release profiles of the prepared beads with curcumin indicated that the curcumin release was significantly increased compared with the dissolution of curcumin itself. The cumulative release of curcumin from the beads was achieved within 24 h, with a final release rate of 12.07% (gastric fluid) as well as 81.93% (intestinal fluid). Both the in vitro and in vivo studies showed that new hydrogel beads based on carbohydrates and poloxamer improved curcumin's bioavailability, and they can be used as powerful carriers for the oral delivery of different hydrophobic nutraceuticals.


Subject(s)
Alginates , Curcumin , Alginates/chemistry , Carrageenan/chemistry , Curcumin/chemistry , Delayed-Action Preparations/chemistry , Drug Carriers/chemistry , Hydrogels/chemistry , Hydrogen-Ion Concentration , Poloxamer
8.
Medicina (Kaunas) ; 58(2)2022 Feb 03.
Article in English | MEDLINE | ID: mdl-35208557

ABSTRACT

BACKGROUND: The incidence of hearing loss is constantly increasing and according to the World Health Organization, by 2050, 900 million people will suffer from hearing loss. The main Objective of the study was to determine the differences between the severity of the symptoms of stress, anxiety and depression in participants with varying degrees of sensorineural hearing loss during the COVID-19 pandemic. An additional aim was to examine the extent and manner in which protective face masks impact the communication of people with hearing loss. Matrials and Methods: A cross-sectional study was conducted, which included 160 patients (81 men and 79 women) with bilateral sensorineural hearing loss. The patients' age range was 50 to 80 years. Depending on the degree of hearing loss or pure-tone threshold, the participants were divided into four groups: mild hearing loss, moderate hearing loss, severe hearing loss and profound hearing loss. The research used the Depression, Anxiety and Stress Scale (DASS-21) and a questionnaire in which the participants reported whether surgical face masks (medical three-layer masks) worn by speakers makes communication difficult, to what extent and in what way. RESULTS: The average age of the patients was 67.97 ± 8.16. A significant correlation was found between the degree of hearing loss and communication difficulties caused by the use of protective face masks (p < 0.001). For patients with severe and profound hearing loss, communication is significantly more difficult (50.0% and 45.0% respectively) when the interlocutor wears a face mask. There is a significant correlation between the degree of hearing loss and the way in which communication is made more difficult when the interlocutor wears a face mask (p < 0.001). A statistically significant difference was determined between the degrees of hearing loss in all measured subscales: stress (p = 0.024), anxiety (p = 0.026) and depression (p = 0.016). CONCLUSIONS: We have determined that face masks used during the COVID-19 pandemic significantly hamper communication among the study groups (p = 0.007) and there is a significant correlation between the degree of sensorineural hearing loss and the presence of symptoms in all three DASS-21 subscales, meaning that the symptoms of stress, anxiety and depression were more intense in severe and profound hearing loss.


Subject(s)
COVID-19 , Hearing Loss, Sensorineural , Aged , Aged, 80 and over , Anxiety/epidemiology , Cross-Sectional Studies , Depression/epidemiology , Female , Hearing Loss, Sensorineural/epidemiology , Humans , Male , Middle Aged , Pandemics , SARS-CoV-2
9.
Bioorg Med Chem Lett ; 46: 128194, 2021 08 15.
Article in English | MEDLINE | ID: mdl-34116160

ABSTRACT

Twenty novel 2-substituted quinoline-4-carboxylic acids bearing amide moiety were designed and synthesized by Doebner reaction. Human dihydroorotate dehydrogenase (hDHODH) was recognized as a biological target and all compounds were screened as potential hDHODH inhibitors in an enzyme inhibition assay. The prepared heterocycles were also evaluated for their cytotoxic effects on the healthy HaCaT cell line while lipophilic properties were considered on the basis of experimentally determined logD values at physiological pH. The most promising compound 5j, with chlorine at para-position of terminal phenyl ring, showed good hDHODH inhibitory activity, low cytotoxicity, and optimal lipophilicity. The bioactive conformation of 5j on the hDHODH, determined by means of molecular docking, revealed the compound's pharmacology and provide guidelines for further lead optimization.


Subject(s)
Antineoplastic Agents/pharmacology , Benzaldehydes/chemistry , Dihydroorotate Dehydrogenase/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Quinolines/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Line , Cell Survival/drug effects , Dihydroorotate Dehydrogenase/metabolism , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Humans , Molecular Structure , Quinolines/chemistry , Structure-Activity Relationship
10.
Endocr Pract ; 27(11): 1077-1081, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34216799

ABSTRACT

OBJECTIVE: Medullary thyroid carcinoma (MTC) can be very aggressive, and early diagnosis is based on routine measurement of serum calcitonin (CT) and RET genetic testing for hereditary forms. Basal serum CT (bCT) concentrations are useful in the early detection of MTC, although it is still unclear whether they can also be used for the differential diagnosis between MTC and C-cell hyperplasia (CCH). Since false-positive results can be obtained with the basal measurement of CT, a provocative test to evaluate stimulated CT (sCT) is often needed. The objective of this study was to investigate the utility of a calcium gluconate test for CT in distinguishing MTC from CCH, a precancerous condition in hereditary forms of MTCs but with unclear significance in sporadic MTCs. METHODS: A total of 74 patients underwent the calcium loading test before thyroidectomy, and bCT and sCT levels were compared with histologic results by receiver operating characteristic plot analyses. RESULTS: A peak CT level of 388.4 pg/mL after stimulation with calcium gluconate was able to significantly distinguish patients with MTC from those with CCH and those without C-cell pathology, with 81.8% sensitivity and 36.5% specificity. A bCT level of 16.1 pg/mL was able to distinguish between these 2 groups of patients with a sensitivity of 90%. CONCLUSION: High-dose calcium test is an effective procedure that can be applied for differential diagnosis of MTC and CCH. Reference ranges for calcium sCT levels and CT thresholds in different groups of patients have been identified.


Subject(s)
Carcinoma, Medullary , Thyroid Neoplasms , Biomarkers, Tumor , Calcitonin , Calcium , Humans , Thyroid Neoplasms/diagnosis , Thyroid Neoplasms/surgery , Thyroidectomy
11.
Bioorg Chem ; 105: 104373, 2020 12.
Article in English | MEDLINE | ID: mdl-33074120

ABSTRACT

A series of novel 2-substituted quinoline-4-carboxylic acids was synthesized by Doebner reaction starting from freely available protocatechuic aldehyde and vanillin precursors. Human dihydroorotate dehydrogenase (hDHODH) was recognised as a clear molecular target for these heterocycles. All compounds were also tested for their antiproliferative potential against three cancer cells (MCF-7, A549, A375) and one normal cell line (HaCaT) to evaluate the selective cytotoxicity. Quinoline derivatives 3f and 3g were identified as potent hDHODH inhibitors while 3k and 3l demonstrated high cytotoxic activity against MCF-7 and A375 cells and good selectivity. In addition, the logD7.4 values obtained by the experimental method were found to be in the range from -1.15 to 1.69. The chemical structures of all compounds were confirmed by IR, NMR and elemental analysis. The compounds pharmacology on the molecular level was revealed by means of molecular docking, highlighting the structural differences that distinguish highly active from medium and low active hDHODH inhibitors.


Subject(s)
Aldehydes/pharmacology , Antineoplastic Agents/pharmacology , Enzyme Inhibitors/pharmacology , Molecular Docking Simulation , Oxidoreductases Acting on CH-CH Group Donors/antagonists & inhibitors , Phenols/pharmacology , Quinolines/pharmacology , Aldehydes/chemistry , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Line , Cell Proliferation/drug effects , Cell Survival/drug effects , Dihydroorotate Dehydrogenase , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Humans , Hydrophobic and Hydrophilic Interactions , Molecular Structure , Oxidoreductases Acting on CH-CH Group Donors/metabolism , Phenols/chemistry , Quinolines/chemical synthesis , Quinolines/chemistry , Structure-Activity Relationship
12.
Chem Biodivers ; 17(2): e1900544, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31840372

ABSTRACT

Geranium species are widely used in traditional medicine of Balkan. The aim of this work was to investigate and compare chemical composition of volatile fractions obtained by hydrodistillation from aerial parts of G. macrorrhizum, G. phaeum, G. sanguineum, G. robertianum, G. palustre, G. pyrenaicum, G. columbinum and G. lucidum as well as from underground parts of G. macrorrhizum and G. phaeum, originated from Vlasina plateau in South Eastern Serbia. The volatiles were analyzed using GC/MS and GC-FID. G. palustre volatiles have been studied for the first time with ß-selinene (18.6 %) as a characteristic compound. The cluster analysis revealed separation of volatiles into two main groups. Volatile fractions of G. macrorrhizum were separated from all other samples due to high sesquiterpene content (92.3 % in aerial and 94.6 % in underground parts). The volatile fractions of other samples were mainly composed of sesquiterpenes (10.8-61.8 %), diterpenes (12.9-43.0 %) and fatty acids and their derivatives (6.6-21.6 %) with the exception of volatile fraction of G. phaeum underground parts which was dominated only by fatty acids and their derivatives (76.6 %). The results presented in this article contribute to the knowledge on the chemistry of this genus and advances the knowledge on flora of southeast Serbia.


Subject(s)
Geranium/chemistry , Volatile Organic Compounds/chemistry , Cluster Analysis , Gas Chromatography-Mass Spectrometry , Geranium/metabolism , Plant Components, Aerial/chemistry , Plant Components, Aerial/metabolism , Serbia , Sesquiterpenes/chemistry , Sesquiterpenes/isolation & purification , Volatile Organic Compounds/analysis
14.
Bioorg Med Chem Lett ; 28(15): 2593-2598, 2018 08 15.
Article in English | MEDLINE | ID: mdl-29970309

ABSTRACT

A series of 23 novel anthraquinone-chalcone hybrids containing amide function was synthesized and structurally characterized. Sixteen compounds exerted strong cytotoxic activities against K562, Jurkat and HL-60 leukemia cell lines and significantly lower cytotoxic effects against normal MRC-5 cells, indicating very high selectivity in their anticancer action. The compounds 6g, 6u and 6v activate apoptosis in K562 cells through the extrinsic and intrinsic apoptotic pathway. The compound 6e triggered apoptosis in K562 cells only through the extrinsic apoptotic pathway. Treatment of K562 cells with each of these four compounds caused decrease in the expression levels of MMP2, MMP9, and VEGF, suggesting their anti-invasive, antimetastatic and antiangiogenic properties. The compounds 6g and 6v downregulated expression levels of miR-155 in K562 cells, while compounds 6e and 6u upregulated miR-155 levels in treated cells, in comparison with control cells. The structure-based 3-D QSAR models for 6f, 6e, 6i and 6l describe pro-apoptotic activity against caspase-3.


Subject(s)
Anthraquinones/chemistry , Antineoplastic Agents/therapeutic use , Chalcones/chemistry , Leukemia/drug therapy , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Carbon-13 Magnetic Resonance Spectroscopy , Caspase 3/metabolism , Drug Screening Assays, Antitumor , HL-60 Cells , Humans , Jurkat Cells , K562 Cells , Leukemia/enzymology , Leukemia/pathology , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , MicroRNAs/metabolism , Neoplasm Invasiveness/prevention & control , Neoplasm Metastasis/prevention & control , Neovascularization, Pathologic/prevention & control , Proton Magnetic Resonance Spectroscopy , Quantitative Structure-Activity Relationship , Vascular Endothelial Growth Factor A/metabolism
15.
Anal Chem ; 89(11): 5882-5890, 2017 06 06.
Article in English | MEDLINE | ID: mdl-28497696

ABSTRACT

A new approach to achieving chemical mapping on a nanoscale is described that can provide 2D and tomographic images of surface and near-surface structure. The method comprises dissolving material from the surface of the sample by applying a series of aliquots of solvent, then analyzing their contents after removing them; in between exposures, the surface is imaged with atomic force microscopy. This technique relies on being able to compensate for any drift between images by use of software. It was applied to a blend of two polymers, PMMA and PS. The analytical data identified the material that was dissolved, and the topography images enabled the location of the various materials to be determined by analyzing local dissolution kinetics. The prospects for generalizing the approach are discussed.

16.
Bioorg Med Chem Lett ; 27(16): 3709-3715, 2017 08 15.
Article in English | MEDLINE | ID: mdl-28709826

ABSTRACT

Two 2-amino-1,3,4-thiadiazoles containing phenolic hydroxyl groups were combined with different carboxylic acid chlorides giving sixteen amide derivatives with good antioxidant and antiproliferative potential. The compound 3'c with an adamantane ring displayed excellent DPPH radical scavenging activity and good cytotoxic activity against human acute promyelocytic leukemia HL-60 cells, while 1,3,4-thiadiazole 3'h with 4-chlorophenyl moiety was found to be the most effective in inhibition of survival of lung carcinoma A549 cells. All examined thiadiazoles except 3a and 3'a exerted higher cytotoxic activities on A549 and HL-60 cancer cells when compared with normal fibroblasts MRC-5, pointing to selectivity in their antiproliferative action. Some of the most active novel compounds 3c, 3'c, 3'g and 3'h induced significant increase in the percentage of HL-60 cells in the subG1 cell cycle phase in comparison with the control cells. The induction of cell death in HL-60 cells by these compounds was at least partially dependent on activation of caspase-3 and caspase-8. The compounds 3c and 3'c exerted strong antiangiogenic activity. Furthermore, compounds 3c, 3'c, 3'g and 3'h showed the ability to down-regulate the MMP2 and VEGFA expression levels in the treated HL-60 cells when compared with the control cell samples.


Subject(s)
Hydroxybenzoates/chemistry , Thiadiazoles/chemistry , Thiadiazoles/pharmacology , A549 Cells , Angiogenesis Inhibitors/chemical synthesis , Angiogenesis Inhibitors/chemistry , Angiogenesis Inhibitors/pharmacology , Antioxidants/chemical synthesis , Antioxidants/chemistry , Antioxidants/pharmacology , Caspase 3/metabolism , Caspase 8/metabolism , Cell Line , Cell Proliferation/drug effects , Cell Survival/drug effects , Down-Regulation/drug effects , G1 Phase Cell Cycle Checkpoints/drug effects , HL-60 Cells , Humans , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Structure-Activity Relationship , Thiadiazoles/chemical synthesis , Vascular Endothelial Growth Factor A/metabolism
17.
Phys Chem Chem Phys ; 19(11): 8061-8068, 2017 Mar 15.
Article in English | MEDLINE | ID: mdl-28265621

ABSTRACT

Graphite surfaces can be manipulated by several methods to create graphene structures of different shapes and sizes. Scanning tunneling microscopy (STM) can be used to create these structures either through mechanical contact between the tip and the surface or through electro-exfoliation. In the latter, the mechanisms involved in the process of exfoliation at an applied voltage are not fully understood. Here, we show how a graphite surface can be locally exfoliated in a systematic manner by applying an electrostatic force with a STM tip at the edge of a terrace, forming triangular flakes several nanometers in length. We demonstrate, through experiments and simulations, how these flakes are created by a two-step process: first a voltage ramp must be applied at the edge of the terrace, and then the tip must be scanned perpendicular to the edge. Ab initio electrostatic calculations reveal that the presence of charges on the graphite surface weakens the interaction between layers allowing for exfoliation at voltages in the same range as those used experimentally. Molecular dynamics simulations show that a force applied locally on the edge of a step produces triangular flakes such as those observed under STM. Our results provide new insights into surface modification that can be extended to other layered materials.

18.
Mar Drugs ; 15(10)2017 Sep 25.
Article in English | MEDLINE | ID: mdl-28946687

ABSTRACT

Hydrophilic matrices composed of chitosan (CS) and xanthan gum (XG) complexes are of pharmaceutical interest in relation to drug delivery due to their ability to control the release of active ingredients. Molecular dynamics simulations (MDs) have been performed in order to obtain information pertaining to the effect of the state of protonation and degree of N-acetylation (DA) on the molecular conformation of chitosan and its ability to interact with xanthan gum in aqueous solutions. The conformational flexibility of CS was found to be highly dependent on its state of protonation. Upon complexation with XG, a substantial restriction in free rotation around the glycosidic bond was noticed in protonated CS dimers regardless of their DA, whereas deprotonated molecules preserved their free mobility. Calculated values for the free energy of binding between CS and XG revealed the dominant contribution of electrostatic forces on the formation of complexes and that the most stable complexes were formed when CS was at least half-protonated and the DA was ≤50%. The results obtained provide an insight into the main factors governing the interaction between CS and XG, such that they can be manipulated accordingly to produce complexes with the desired controlled-release effect.


Subject(s)
Chitosan/chemistry , Polysaccharides, Bacterial/chemistry , Acetylation , Hydrophobic and Hydrophilic Interactions , Molecular Dynamics Simulation , Static Electricity , Water/chemistry
19.
Eur Arch Otorhinolaryngol ; 274(2): 997-1004, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27619822

ABSTRACT

The thyroid gland disease incidence in hyperparathyroidism (HPT) is higher than the incidence of thyroid disease in general population. Likewise, HPT is more frequent in patients primary admitted due to thyroid disease, than in general population. The aim of this study was to determine the incidence and clinical characteristics of concomitant HPT and thyroid disease, based on a single center experience. From 2009 to 2014, a total of 4882 patients underwent thyroidectomy and/or parathyroidectomy at the Center for Endocrine Surgery, Belgrade. We reviewed the database to find out indications for surgery, clinical characteristics, operative and histopathological findings. Out of 4033 patients, who underwent thyroidectomy, in 114 cases (2.8 %) parathyroidectomy was simultaneously performed. Out of these 114 patients, 42 patients (37 %) had normocalcemic HPT. Among 849 patients primary operated due to HPT, thyroid gland disease that required surgery was found in 224 (26.4 %). In patients primary seen for HPT, thyroid cancer was found in 22 (9.8 %), Hashimoto's thyroiditis in 41 (18.3 %) and micropapillary carcinoma in 36 cases (16.1 %). Due to residual or recidivant HPT, 16 patients (15 who primary underwent parathyroidectomy and 1 primary seen for thyroid disease) needed a reoperation. There are a considerable number of patients with concomitant thyroid and parathyroid disease; this justifies the routine analyses of calcemia and PTH level in patients preparing for thyroidectomy, and sets up the ground for the thyroid investigations in HPT.


Subject(s)
Hyperparathyroidism/surgery , Parathyroidectomy/methods , Thyroid Diseases/surgery , Thyroidectomy/methods , Female , Humans , Hyperparathyroidism/complications , Male , Middle Aged , Thyroid Diseases/complications , Treatment Outcome
20.
Cleft Palate Craniofac J ; 54(6): 650-655, 2017 11.
Article in English | MEDLINE | ID: mdl-27441700

ABSTRACT

OBJECTIVE: The purpose of this study was to assess the effect of ventilation tube (VT) placement on long-term hearing outcomes in children with cleft palate. STUDY DESIGN: Case series with chart review. SETTING: Genetic and dysmorphology database at Rady Children's Hospital-San Diego (RCHSD). PATIENTS: Children with cleft palate diagnosis who underwent surgery at RCHSD between 1995 and 2002. MAIN OUTCOME MEASURE: The primary outcome studied was hearing acuity at 10 years of age. Independent variables studied included gender, age at palate repair and first VT placement, total number of VTs, number of complications, and presence of tympanic membrane perforation. RESULTS: An increased number of tubes was associated with a greater incidence of hearing loss at age 10, even after adjusting for total number of otologic complications. The timing of initial tube placement did not have a significant effect on long-term hearing outcome in this study. CONCLUSIONS: While children with worse middle ear disease are more likely to receive more tubes and have long-term conductive hearing loss as a result of ear disease, the results of this study suggest that multiple tube placements may not contribute to improved long-term hearing outcomes. Further research focusing on long-term outcomes is needed to establish patient-centered criteria guiding decision making for ventilation tube placement in children with cleft palate.


Subject(s)
Cleft Palate/surgery , Hearing Loss/etiology , Middle Ear Ventilation/adverse effects , Otitis Media with Effusion/therapy , Audiometry, Pure-Tone , Child , Female , Humans , Male , Treatment Outcome
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